Sprite Kit Scenes and SKNode Positioning - Beginning Swift Games Development for iOS - page 23

At this point, the node tree contains three nodes— node1 , node2 , and node3 (in that
order). Now, if you executed the following snippet, you would have a node tree that
looked like Figure 2-3 :
var node4 = SKSpriteNode()
gameScene.insertChild(node4, atIndex: 2)
Figure 2-3 . The gameScene's node tree after inserting a fourth node
The children property now contains four nodes, with node4 being inserted between
node2 and node3 . Let's do one last thing and remove a node.
node2.removeFromParent()
By invoking node2 's removeFromParent method, you have removed node2 from
its parent, which is gameScene in this case. Now the node tree looks like Figure 2-4 .
Figure 2-4 . The gameScene's node tree after removing node4
There is one last thing you need to look at, and that is nested nodes. Because the node tree
is part of SKNode and because SKSpriteNode is extended from SKNode , it can have